Influence of Lauric Acid as a phase change material for solar distillation

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Water is one of the precious resources to living organism. It is used in many activities like drinking, washing and irrigation etc. but the people is facing scarcity of pure drinking water due to continuously increasing industrial development, intensified agriculture, improvement of standard of life and increase of the world population. Therefore, contaminated water available from various sources (rain water, boring wells, rivers, lakes, oceans, etc.) must be purified. These impurities can be removed from the contaminated water by using solar distillation technique. Distillation is one of the popular treatment solutions throughout of the world. Performance of solar distillation systems depend on climatic parameters such as ambient temperature, solar radiation intensity and weather
condition etc., design parameters like inclination angle and operational parameters like orientation of solar still and brine water depth.


• To maximize the distillate output from solar still using phase change material.
• To find out the most suitable PCM for solar distillation in Indian climatic conditions.
• To study the influence of copper cylinder in the quality of distillate, and also study
aluminium cylinders for the same purpose and compare the results.
• To study the efficacy of distillate to be used as drinking water.


The solar radiation is transmitted through the glass cover and it is absorbed by the phase change material (PCM) and basin; hence these temperatures increase. Part of the energy absorbed by the basin is transmitted by the convection to the basin water. As the copper cylinder are heated. Heat is first stored as a sensible heat until the PCM reaches its melting point. At this time, PCM starts to melt and after complete melting of the PCM, the heat will be stored in the melted PCM as a sensible heat. After the sunset, when the solar radiation decrease, the still components start to cool down and the liquid PCM transfers heat to the basin liner and from the latter to the basin water until the PCM completely solidified. The PCM act as a heat source for the basin water during low intensity to solar radiation periods as well as during the night; consequently the still continues to produce pure water after sunset even thin layers of basin water.

Results & Discussions

The presented work deals with performance evaluation of basin type and solar still with and without PCM using experimental set up. We are comparing the efficiency of both still.


A single-slope solar still has been fabricated and experiments were carried out to obtain distillate under Varanasi (U.P.) weather conditions. Lauric acid as a phase change material (PCM) was kept inside six copper cylinders and kept inside the basin to study the enhancement of distillate output for a 24-hour period (overnight productivity). From the results achieved on typical summer days, the following
conclusions may be drawn:
1. The distillate output from the solar still is directly proportional to intensity of solar radiation.
2. After sunset, the PCM acts as a heat source for the basin water until early morning of the next day.
3. The daylight productivity is found to decrease slightly with increasing the mass of PCM; however, the overnight productivity and daily productivity significantly increased with increasing mass of PCM.
4. Productivity of solar still is inversely proportional to the depth of water in basin.


Sonker VK, Chakraborty JP, Sarkar A. Solar distillation using three different phase change materials stored in a copper cylinder. Energy Reports. 2019;5:1532-42.